Error Testing

Albert van der Horst albert at spenarnc.xs4all.nl
Wed Oct 30 17:43:30 EDT 2013


In article <mailman.1272.1382221693.18130.python-list at python.org>,
Chris Angelico  <rosuav at gmail.com> wrote:
>On Sun, Oct 20, 2013 at 3:22 AM, rusi <rustompmody at gmail.com> wrote:
>> The problem is that python is an imperative language and uses the '=' sign for assignment.  In math of course
>'=' stands for equality.
>
>Pascal tried to create a new operator, := to be read "becomes", to
>deal with the whole equality-vs-assignment issue. Did it really help
>anything? I don't think so. Just syntactic salt. Even the comparison
>isn't really mathematical - in maths, "x = y" is a statement of truth,
>whereas in programming, it's a question ("is x equal to y").

This suggests that Pascal went against established practice.
This is false. FORTRAN used = and that was a mistake caused by the
language being hacked together haphazardly. Langages that where
designed (ALGOL60 SIMULA ALGOL68 Pascal ADA) all use :=.
C C++ Java C# use = for assignment because of the inertia caused
by FORTRAN. Pascal was created in a culture where it using = would
be unexpected.

Knuth uses k<-n exactly because k=n would cause confusion.

The equivalent of the dreaded
if ( x=getch())
{
}

is possible in ALGOL68 too. It is not likely to be misunderstood
because of the use of :=.

By the way, it is about the only thing that I think is wrong in
Python.

>
>
>ChrisA

Groetjes Albert
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert at spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst




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